The Trump administration - which canceled two large-scale spring war games between the United States and South Korea in an effort to move along nuclear disarmament talks with North Korea - is now grappling with reports that Pyongyang is preparing to launch a missile soon.
The reports follow President Trump and North Korean leader Kim Jong Un's failure to reach an agreement at their summit last month. North Korea's account for the failure differs from Trump's, a fact that has increased tensions between the countries.
Experts warn that tensions could rise before negotiations move forward.
"I worry a little bit that this could get worse before it gets better because both sides want to try to figure out how to get the other side back to the table," said Victor Cha, a former official in charge of Korea relations in the George W. Bush administration. "And they may say pressure is the way to do that."
National security adviser John Bolton on Sunday said Trump would be "pretty disappointed" should North Korea carry out a nuclear test or a missile launch.
Bolton had been asked about new commercial satellite images taken Friday that show activity at a North Korean missile site near the border with China. Beyond Parallel, a project started by the Center for Strategic and International Security (CSIS), said North Korea "has continued preparations on the launch pad" at the Sohae launch facility, a sign the country is readying for "the delivery of a rocket."
The long-range rocket launch site was previously shut down as part of a promise made between Kim and Trump at their first summit in June in Singapore.
Experts view the rebuilding as "deliberate efforts by North Korea in response to the inconclusive results of the Hanoi summit - to send a message, really, to President Trump and the world," according to Cha.
Cha, now with CSIS, warned Thursday that tensions could continue to rise between Washington and Pyongyang before things cool down.
North Korea's biggest ask in negotiations - the lifting of major sanctions imposed by U.N. Security Council resolutions - has shown "that they see that pressure as troublesome," he said.
"One of the lessons, I think, that both sides took away from the summit is that pressure works. ... And then you see, in terms of our imagery, that the North Korean response is to go back to some of these sites that they know bother us, whether it's the nuclear test site or the Sohae satellites - launch site - and say, 'Look, we're going to start doing some stuff here too.'"
The launch facility developments are troubling for the administration, which had nixed military exercises on the Korean Peninsula in favor of several smaller-scale drills meant to maintain readiness but still appease Kim's government.
The United States earlier this month canceled the larger drills, known as Key Resolve and Foal Eagle, in favor of the smaller Dong Maeng, which runs from March 4 to March 12.
Trump earlier this month wrote on Twitter that he canceled the bigger exercises "to save hundreds of millions of dollars for the U.S. for which we are not reimbursed."
But North Korea on Thursday appeared to reject the major compromise Trump made following the summit in Hanoi, blasting the scaled-back exercises as a "violent violation," and a "frontal challenge to the aim and desires of all [Korean] people and the international community for peace and stability on the Korean Peninsula."
Adding to the tensions, Bolton on Sunday made clear that the administration would not back down in the face of further provocations from Pyongyang.
"I think Kim Jong Un has a very clear idea where the president stands," he said.
Trump "has been very clear that he's not going to make the mistakes of prior administrations," including believing North Korea will "automatically comply when they undertake obligations," Bolton said on ABC's "This Week."
Bolton would not specifically address reports on North Korea's recent moves, saying only that "there's a lot of activity all the time in North Korea" and that "nothing in the proliferation game surprises me anymore."
"That's one reason why we pay particular attention to what North Korea is doing," he added.
Trump numerous times this past week said he'd be "very disappointed" if Pyongyang was preparing to launch another missile or rocket.
The admission of possible backward momentum is a rare step for Trump, who famously declared after the Singapore summit that "there is no longer a Nuclear Threat from North Korea."
Trump also said in June that Kim had told him the country was "already destroying" the Sohae facility.
"That's a big thing," Trump told reporters at the time. "The site is going to be destroyed very soon."
But Trump, who abruptly ended talks with Kim last week in Vietnam, said North Korea had asked for too much in terms of lifting sanctions.
Trump appeared to remain defiant in the face of growing reports of a North Korean ramp-up, telling reporters Friday that he would be "surprised" by any preparations for a missile test.
"Well, time will tell, but I have a feeling that our relationship with North Korea - Kim Jong Un and myself, Chairman Kim - I think it's a very good one," he said.
It remains to be seen whether the president's optimism will stand, but experts, for the time being, are not expecting an immediate return to the days of "fire and fury," when Trump and Kim exchanged nuclear threats.
"I don't think it's necessarily North Korea's return to provocations," said Dr. Sue Mi Terry, a former senior analyst at the CIA and a former National Security Council staffer.
Dr. Terry, now with CSIS, said the moves should not "be taken as a sign that they're going to return to missile testing or nuclear testing. I think right now it's a signal they are trying to send to show their resolve."
And Harry Kazianis, director of defense studies at the Center for the National Interest, said North Korea's recent display of outrage over the U.S.-South Korean military drills was a routine display.
"Even if there had been a deal, they would still have reacted the same way," Kazianis told The Hill. "Maybe with a little less gusto, but they still would have complained no matter what."